[Proj] ESRI proj codes

[Melita Kennedy]

>Date: Thu, 8 Sep 2011 08:16:18 -0700
>From: Eric Miller <EMiller at dfg.ca.gov>
>Subject: Re: [Proj] ESRI proj codes
>To: <proj at lists.maptools.org>
>
>ESRI documents the various codes in their online help.  I'm not sure if there is a single place for all of them (outside the SDK header file pedef.h which is considered a "trade secret").  For instance, the C++ API has several projection related constants.
>
>http://help.arcgis.com/en/sdk/10.0/arcobjects_cpp/componenthelp/index.html#/esriSRProjCSType_Constants/000w0000003q000000/
>
>And geographic coordinate systems ...
>
>http://help.arcgis.com/en/sdk/10.0/arcobjects_cpp/componenthelp/index.html#/esriSRGeoCSType_Constants/000w0000002t000000/
>-- 
>
>Eric G. Miller
>Staff Programmer
>CA Dept. of Fish & Game
>
>
>>>> On 9/8/2011 at 6:32 AM, Irwin Scollar <al001 at uni-koeln.de> wrote:
>> The NAD directory of proj4 contains the files esri and esri-other 
>> with additional codes numbered above 100000.
>> 
>> These useful additional codes are not recognized by the EPSG web site 
>> http://www.epsg-registry.org/. They are also not in the official 
>> Access database file EPSG_v7_9.mdb.   They are however linked on the 
>> http://spatialreference.org/ref/epsg/ site.
>> 
>> Is there an Internet source for the latest ESRI data which can be 
>> used to create a supplementary table for the EPSG Access database and 
>> which can be updated when ESRI or EPSG adds or changes something?
>> 
>> Irwin Scollar

Irwin, 

There currently is not a complete list available online. The ArcObjects enumeration lists are not complete. These are definitions defined by Esri. Sometimes EPSG adds the definitions later, and then Esri updates the well-known IDs to the EPSG one (as more authoritative). Some are beyond the scope of EPSG, like the county-level or multi-county-level systems in use in some US states.

Eric, 

The pedef.h file is not considered a trade secret! It used to be included in the online help for ArcSDE, but I believe we stopped that when the files got pretty large. It's not really enough information to build the PROJ tables. You would need access to the well-known text strings, or the PE library to get the parameters, unit, gcs, etc.

Melita